A utility for basic data cleaning and recoding. Changes values outside of minimum and maximum limits to NA.

Description

A tedious part of data analysis is addressing the problem of miscoded data that need to be converted to NA or some other value. For a given data.frame or matrix, scrub will set all values of columns from=from to to=to that are less than a set (vector) of min values or more than a vector of max values to NA. Can also be used to do basic recoding of data for all values=isvalue to newvalue.

The length of the where, isvalue, and newvalues must either match, or be 1.

Usage

scrub(x, where, min, max,isvalue,newvalue)

Arguments

x

a data frame or matrix

where

The variables to examine. (Can be by name or by column number)

min

a vector of minimum values that are acceptable

max

a vector of maximum values that are acceptable

isvalue

a vector of values to be converted to newvalue (one per variable)

newvalue

a vector of values to replace those that match isvalue

Details

Solves a tedious problem that can be done directly but that is sometimes awkward. Will either replace specified values with NA or

Value

The corrected data frame.

Note

Probably could be optimized to avoid one loop

Author(s)

William Revelle

See Also

Examples

data(attitude)
x <- scrub(attitude,isvalue=55) #make all occurrences of 55 NA
x1 <- scrub(attitude, where=c(4,5,6), isvalue =c(30,40,50),
newvalue = c(930,940,950)) #will do this for the 4th, 5th, and 6th variables
x2 <- scrub(attitude, where=c(4,4,4), isvalue =c(30,40,50),
newvalue = c(930,940,950)) #will just do it for the 4th column
#get rid of a complicated set of cases and replace with missing values
y <- scrub(attitude,where=2:4,min=c(20,30,40),max= c(120,110,100),isvalue= c(32,43,54))
y1 <- scrub(attitude,where="learning",isvalue=55,newvalue=999) #change a column by name
y2 <- scrub(attitude,where="learning",min=45,newvalue=999) #change a column by name
y3 <- scrub(attitude,where="learning",isvalue=c(45,48),
newvalue=999) #change a column by name look for multiple values in that column
y4 <- scrub(attitude,where="learning",isvalue=c(45,48),
newvalue= c(999,-999)) #change values in one column to one of two different things